The present invention relates to a spinal fixation system connector for maintaining predetermined positions of vertebrae in the spinal column of a patient. More particularly, the present invention relates to a component of a spinal fixation system for connecting a first spinal linkage member (e.g., a rod) to a second spinal linkage member. The component allows angles between the connected spinal linkage members to vary.
Spinal fixation systems are commonly used to align, adjust and/or stabilize portions of a spinal column of a patient. These systems frequently include vertebral anchors such as pins, bolts, screws, hooks and/or cables that attach to vertebrae in the spinal column. The spinal linkage members can be connected to the anchors to maintain the relative positions of the corresponding vertebrae. Thus, the members maintain the spacing and alignment of the connected vertebrae. To provide desired alignment across several levels of the spine, more than one spinal linkage member may be used and connected by one or more fixation system connectors.
Frequently, the connector is used to connect portions of two linkage members positioned side-by-side. The connector spans between linkage members to maintain the positions of the members relative to each other. Frequently, the portions of the spinal linkage members connected by the connector are not parallel. Instead, the members are non-parallel so they are oriented at various angles and in various positions due to the anatomical structure of the spine and alignment desired by the surgeon.
Many conventional connectors are designed to accommodate linkage members aligned at a particular angle. Variations in angular alignment from the particular angle accepted by the linkage may make it difficult to optimally align members using the conventional connectors. When there is a difference between the desired alignment and the fixed alignment of conventional connectors, the linkage members must be deformed. Deforming members may weaken portions of the spinal fixation system or cause the vertebrae to fail.